PMID- 12509430
OWN - NLM
STAT- MEDLINE
DCOM- 20030423
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 278
IP  - 10
DP  - 2003 Mar 7
TI  - Mammalian Ric-8A (synembryn) is a heterotrimeric Galpha protein guanine 
      nucleotide exchange factor.
PG  - 8356-62
AB  - The activation of heterotrimeric G proteins is accomplished primarily by the 
      guanine nucleotide exchange activity of ligand-bound G protein-coupled receptors. 
      The existence of nonreceptor guanine nucleotide exchange factors for G proteins 
      has also been postulated. Yeast two-hybrid screens with Galpha(o) and Galpha(s) 
      as baits were performed to identify binding partners of these proteins. Two 
      mammalian homologs of the Caenorhabditis elegans protein Ric-8 were identified in 
      these screens: Ric-8A (Ric-8/synembryn) and Ric-8B. Purification and biochemical 
      characterization of recombinant Ric-8A revealed that it is a potent guanine 
      nucleotide exchange factor for a subset of Galpha proteins including Galpha(q), 
      Galpha(i1), and Galpha(o), but not Galpha(s). The mechanism of Ric-8A-mediated 
      guanine nucleotide exchange was elucidated. Ric-8A interacts with GDP-bound 
      Galpha proteins, stimulates release of GDP, and forms a stable nucleotide-free 
      transition state complex with the Galpha protein; this complex dissociates upon 
      binding of GTP to Galpha.
FAU - Tall, Gregory G
AU  - Tall GG
AD  - Department of Pharmacology, University of Texas Southwestern Medical Center, 
      Dallas 75390-9041, USA.
FAU - Krumins, Andrejs M
AU  - Krumins AM
FAU - Gilman, Alfred G
AU  - Gilman AG
LA  - eng
SI  - GENBANK/AY177754
SI  - GENBANK/AY177755
GR  - GM34497/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
DEP - 20021230
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Caenorhabditis elegans Proteins)
RN  - 0 (Guanine Nucleotide Exchange Factors)
RN  - 0 (Nuclear Proteins)
RN  - 0 (Ric8a protein, rat)
RN  - 0 (Ric8b protein, rat)
RN  - EC 3.6.5.1 (Heterotrimeric GTP-Binding Proteins)
SB  - IM
MH  - Animals
MH  - Caenorhabditis elegans Proteins/*metabolism
MH  - Chromatography, Gel
MH  - Cloning, Molecular
MH  - *Guanine Nucleotide Exchange Factors
MH  - Heterotrimeric GTP-Binding Proteins/genetics/isolation & purification/*metabolism
MH  - Molecular Sequence Data
MH  - Nuclear Proteins/*metabolism
MH  - Rats
MH  - Two-Hybrid System Techniques
EDAT- 2003/01/02 04:00
MHDA- 2003/04/24 05:00
CRDT- 2003/01/02 04:00
PHST- 2003/01/02 04:00 [pubmed]
PHST- 2003/04/24 05:00 [medline]
PHST- 2003/01/02 04:00 [entrez]
AID - S0021-9258(20)86459-X [pii]
AID - 10.1074/jbc.M211862200 [doi]
PST - ppublish
SO  - J Biol Chem. 2003 Mar 7;278(10):8356-62. doi: 10.1074/jbc.M211862200. Epub 2002 
      Dec 30.